Resilient cushion insert



F. L. HAUSHALTER RESILIENT CUSHION INSERT Feb. '9, 1960 5 Sheets-Sheet 1Filed Jan. 15, 1957 I v INVENTOR. FRED L.HAU$HALTER BY Mm My ATTORNEYSFeb; 9, 1960 HAUSHALTER 2,924,470

RESILIENT CUSHION INSERT Filed Jan. 15, 1957 3 Sheets-Sheet 2 FIGS.

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INVENTOR.

FRED L. HAUSHALTER BY W/MM WyW ATTORNEYS Feb. 9, 1960 F. L. HAUSHALTER2,924,470

RESVILIENT CUSHION INSERT Filed Jan. 15, 1957 Y 3 Sheets-Sheet 5 INVENTOR.

FRED L. HAUSHALTER BY WW4) WV ATTO R N EYS RESILIENT CUSHION INSERT FredL. Haushalter, Pontiac, Mich.

Application January 15, 1957, Serial No. 634,221

3 Claims. (Cl. 287126) The invention relates to a resilient cushioninserts and forms a continuation-in-part of my former application forpatent Serial No. 542,354, filed October 24, 1955. In the saidapplication a method is described for introducing into a recess within arigid member a resilient insert of rubber-like material which inunstressed condition is of a transverse dimension greater than that ofthe recess in which it is inserted. Thus, when in place it has atendency to expand, exerting a strong pressure against the walls of therecess so as to be frictionally retained therein and without thenecessity of vulcanization or other attachment to said walls. Thesubject matter of the present case is a structure having such insert,one specific example of which is a track shoe for an endless track typetractor. An essential feature as above stated is that the insert whenunstressed is of a greater transverse dimension than that of the recess.There are, however, other advantageous features of this structure ashereinafter set forth.

In the accompanying drawings:

Figure 1 is a cross section on line 1-1 of Figure 4 through a recessedrigid body having a prestressed rubber-like insert therein.

Figure 2 is a cross section illustrating one method of installing theinsert within the rigid body and simultaneously pretensioning the same.

Figure 3 is a similar view showing a slightly modified construction.

Figure 4 is an elevation partly in section of a track bar for an endlesstrack type tractor having ,a resilient cushion insert therein.

Figure 5 is a bottom plan view of one of the shoes of a modified type ofendless track tractor having a pair of cushion inserts therein.

Figure 6 is a cross section on line 6-6 of Figure 5.

Figure 7 is a section similar to Figure 1 showing a modifiedconstruction.

Figure 8 is a cross section somewhat similar to Figure 3 butillustrating another modification.

Figure 9 is a view showing the manner of introducing the insert ofFigure 8 in its recess.

Figure 10 is a sectional elevation similar to Figure 4 showing anothermodification.

While there are many specific constructions in which a resilient insertof my improved construction would be advantageous, I shall describespecifically only its application to a tractor shoe. It has been thepractice in the past to vulcanize the rubber-like insert to the walls ofthe recess which adds a considerable item to the cost of manufacture.Also, shrinkage of the insert by cooling after vulcanization isdetrimental. Both of these detrimental features are avoided with myconstruction, which is as follows:

As shown in Figure '1 the rigid member A is of U-shaped cross section toform a channel-shaped recess within which is placed the elongatedresilient insert B. Figure 2 shows the insert B as originally of greatercross-sectional width than the recess within the memited States Patent 0ice her A. Such insert B is also provided centrally with alongitudinally extending thin slot B which extends in depth from itsread edge to within a short distance of its forward edge which asindicated at B is rounded. C is a thin plate-like rigid member withinthe slot B' extending rearward beyond the same. Thus pressure applied onthe outer end of the member C will, as above stated, force the insertedgewise into the recess and at the same time stretch it so as to reduceits width. Figure 3 shows a modified construction in which the insert Dhas a pair of spaced slots D', D extending therein on opposite sides ofthe center thereof. The rigid member -E has corresponding spaced thinplate-like rigid portions E and E for engaging said slots. .This willafford a more stable construction than that illustrated in Figure 2 forforcing the insert into the recess. With both constructions the insertwill be stretched sufiiciently to reduce its width to that of the recessand after complete insertion the rigid members C and B may be withdrawn,whereupon contraction of the stretched member will close the slots B andD, D

However, the contraction in stretched length required for closing theslots is less than the total stretching during insertion so that theinsert is still under stress tending to expand the same transversely.This will insure sufficient frictional cotnact between the insert andthe walls of the recess to retain the former without the necessity ofvulcanization. As the pressure of the member E is applied to the centralportion of the insert and as the side portions thereof are retarded byfriction with the walls of the recess, this central portion will beadvanced to a greater degree than the side portions. This would resultin concaving the outer end of the insert and to avoid such result thecentral portion is originally extended rearward beyond the sideportions. Thus the portion of the insert between the slots D, D projectsrearward at D beyond the portions outside of said slots. Duringinsertion of the member D the friction of the spaced portions E and E ofthe member E on the central portion of the insert which is therebetweenwill draw this projecting portion D inward so that its rear end will bemore nearly in line with the side portions.

Figure 4 is a sectional elevation of one of the transversely extendingtrack bars of an endless track type tractor and of which Figure 1 is across section.- It will be noted that the bar A is of inverted U-shapecross section throughout its length but that the vertical depth inthecentral portion A of the bar is greater than in the end portions A and Athereof. The insert B also extends the full length of the bar and isfashioned to correspond in depth to the portions A, A and A thereof. Itis also provided with one or more longitudinally ex tending slots suchas B, Figure 2, or D, D Figure 3 which slots extend in depth from thelower edge of the insert to within a short distance from the upper edgethereof. Rigid members such as C or E engage these slots and form themeans for prestretching the insert and engaging the same with the bar asabove described. When these rigid members are withdrawn the insert willstill be retained by the resilient stresses remaining therein.

The construction illustrated in Figures 5 and 6 is of a track shoe Fhaving spaced projecting lugs F, F and F at one edge thereof and spacedlugs F and F projecting from the opposite edge for engaging the spacesbetween the aforesaid lugs in the next adjacent shoe and pivotallyconnected thereto. As heretofore constructed, these shoes are formedwith triangular recesses in their underfaces for receiving rubberinserts vulcanized to the metal of the shoe. I have changed theconstruction by forming channel recesses each with parallel side wallsand adjacent respectively with opposite oblique sides of the triangleextending to a common apex. These channels can either beformed in theoriginal casting or, as shown, 7

by spaced bars G and G weldedto thecasting. Cushion inserts H ofresilient rubber-like material are inserted edgewise within saidchannels by the method above described andiby; the; use; of thin rigidmembers, which are in slots.extending the.full. length of; said members-Thus, the. resilient stresses Within the. insert. tending to. expand ittransversely will so. increase; thefriction with. the walls of the.recess; as. to retain the insert; without. the necessity oftvulcanization. Similar: prestretched. inserts. may. be placed inrecesses im thetop. of the. shoe, as indicated at I and 11"..

For some-uses it. may. be desirable to provide. the walls oh the recesswith one on more inwardly projecting lugs which will be. embedded; in.the. insert and will assist in retaining the. same. Such; aconstruction. isshown in Figure 7; in; which the member A hasportions: Jand J. thereof struck inward from opposite walls. to. form said lugs.The insert Brnay beinstalled'by the method previously'described. duringwhich the; lugs J and J will become embedded in. the. rubber;.

As thus. far described the. rigid member. which is: used for stretching.the. insert to reduce. its width is. later Withdrawn. from. its. slot.which W111i be, closed. by the. resiliency of the insert material. Itmay, however, be desirable to leave oneor more of. thesev rigid. memberspermanently within the. resilient insert, such for instance. as, shown.in Figured. Herethespaced thin.rigid mem-bers.E. and E? remain. within.the; insert Di and. also. have. portions E which: project outward.beyond: the. insert. The manner of installingthe insert is illustratedin Figure 9.. wherethe projectingportions.E of the. members E3 and E arefirst engaged. with. slotsdn a head member E? by which they areimpelledto. stretch. the. insert and force it within the recess.If'desireda pingE? may be. used for locking the head E? to the. members;E and E during installation, said pinbeing later removed for detachmentof the head. The projecting portionsE Will-.adda to the traction. insoft ground. Also, they. may beusefnh in. amphibious. vehicles forpropelling them. through. the water. Where. thev rigid members. are tobe. left permanently in the insert itis preferable. that they should beformed of tempered. or hardened. metal.

As shown. in Figure 10. the. projecting portion of the resilient insert:B.is.corrugated=, as. indicated. at El What I claim) as. my invention,is:.

1. A rigid member having a recess thereinv with spaced walls in. fixed.relation to each other, and. an. elongated compressed insert ofrubber-like material disposed edge- Wise forwardly within aprojectingedgewise. rearwardly and outwardly of said.recess,.s aid insertoriginally having a pair of spaced narrow slots intermediate said Wallsdividing the rearward end. ofv said insert into. a, central portion andadjacent. side. portions, said slots extending into. saidinsert fromthe. rearwardedge thereof to. within a short distance of the oppositeforward edge of the insert, said central portion defined by said slotsextending rear- Wardly from the rearward edge of the side portions, theoriginal width of said insert being greater than the distance betweensaid spaced walls, said side portions being stretched into said recessin the direction of the forward edge thereof while said central portionremains unstretched, whereby, when. stretching force is terminated, theouter surface of said central portion is substantially flush with theouter surfaces of. the adjacent side portions of the insert andtheinsert is under compression and in frictional engagement with saidwalls.

2. The combination set. forth in claim 1 further characterized in thatthe side walls of the recess are parallel and the slots are parallel tosaid side walls and to each other.

3. A rigid member having a recess therein with spaced walls in fixedrelation to each other, an elongated compressed insert, of. rubber-like,material disposed edgewise forwardly Within.and. projecting edgewiserearwardly and outwardly of said recess, said insert originally having apair of; spaced narrow slots intermediate said walls dividing therearward end of said insert into a central portion and adjacent side.portions, said slots extending into said: insert from. the. rearwardedge thereof to, Within a; short distance of the. opposite forward edgevof the insert, saidcentral portion. defined; by said. slots extendingrearwardly from the rearward: edge of. the side portions, the originalwidth of said insert. being greater than the distance. between saidspacedwalls, a pair of rigidzforcing blades. inserted; in said slots,said blades forming the means for stretching said insert into.said.recess, said side portions being-stretched intosaid recessin thedirection of the forward edge thereof while said: central portionremains unstretched, whereby, when. stretching force is terminated, theouter surface of said central portion is substantially flush with the.outer surfaces of the adjacent side portions of the insert, and theinsert is under compression and inv frictional; engagement with saidwalls and said blades, said blades thereafter forming part of theassembly.

ReferencesCitedin the file of this patent V UNITED STATES; PATENTS.

831,391 Ubellar Oct. 28, 1905 1,279,386 McEvoy Sept. 17, 1918 2,312,072Broadwater Feb. 23, 1943 2,645,532 H'ollenkamp July 14, 1953 2,686,697Baker Aug. 17, 1954 2,753,886 Powers July 10, 1956 FOREIGN PATENTS339,605 Great Britain Dec. 4, 1930 148,625 Sweden Jan. 25, 1955

